The present invention is directed to a hearing aid having a flexible printed circuit film held in a hearing aid housing.
When designing hearing aids, it is necessary to utilize the extremely small integration space in the hearing aid housing in as rational a manner as possible. The arrangement of the components such as, for example, an acoustic transducer, an energy source, switches, and an amplifier plate thus plays an extremely important role. Moreover, care must be exercised to see that the mounting devices of the individual elements use as little space as possible.
For example, German Utility Model 85 27 362, incorporated herein, discloses a behind-the-ear hearing aid comprising a boxshaped plastic container that is equipped with actuators. This container is combined with further plastic parts to form a structural unit that is arranged between the amplifier plate and the housing. Since the structural unit encompasses mounting elements both for the amplifier plate as well as for the housing, the amplifier plate is held in protected fashion against dislocation with respect to the housing. The structural unit is as rationally designed as possible since it also holds the actuators.
For reasons of saving space, amplifier plates have been arranged on two mounting levels, or the amplifiers have been recently designed as multi-coated, equipped, flexible circuit films. Such an arrangement, however, requires additional holding mechanisms in order to guarantee the spacing between the printed circuit film layers. Such amplifier arrangements having additional spacer projections are disclosed, for example, by German Utility Model No. 79 18 029, corresponding to U.S. Pat. No. 4,354,065, and by U.S. Pat. No. 4,444,318, both incorporated herein.
In order to recover the space lost to the spacing projections, German Utility Model No. 83 28 734 (U.S. Pat. No. 4,639,556), incorporated herein, has proposed that the flexible printed circuit film be clamped in large-area fashion between an operating element and the housing at a bent-off location. This solution, however, has certain disadvantages since the clamped area of the printed circuit film can no longer be used for other purposes. Moreover, this does not yet guarantee protection against dislocation (particularly a protection against turning) for the printed circuit film even if the operating element is held in anti-twist fashion.